1. Field of the Invention
This application relates to hold-downs for fastening a tubular conduit such as a plumbing pipe to a building member, and in particular to such a hold-down having a flexible leg which acts to isolate and insulate the pipe from the building member.
2. Description of the Related Art
Prior art hold-downs for plumbing pipe generally come in two varieties: open and full wraparound. An open hold-down generally includes a rigid back and a claw which extends outwardly from the top of the back. The back includes a nail receiving aperture. A nail extending through the aperture is driven into a building member to secure the hold-down to the building member. The pipe is captured between the claw and the building member.
A problem with this type of hold-down is that a pipe held in the hold-down will be in contact with the building member. As the pipe expands and contracts with changes in temperature it may rub against the building member causing a noise. Such noise is considered undesirable by homeowners. In addition, heat from hot water pipes can be lost through heat transfer from the pipe to the building member.
The full wraparound hold-down completely encompasses the pipe and isolates it from the building member. One type of full wraparound hold-down has a two piece back and a flexible strap which connects the two portions of the back and wraps around the pipe. Again, the back includes a nail aperture which extends through both portions of the back. The pipe is inserted into the hold-down through an opening defined between the two portions of the back. A nail is then inserted through the nail aperture and driven into the building member. The Padlock™ tube strap, manufactured by Sioux Chief Manufacturing Company, Inc. of Peculiar Missouri, is an example of this type of hold-down.
Another variant on the full wraparound type hold-down has an articulated back with a hinge joint midway along its length. A pair of claws extend outwardly from the top and bottom of the back. The hold-down is moveable between open and closed positions by bending the back at the hinge joint. In the closed position the distal ends of the claws are in contact. In the open position an opening is formed between the distal ends of the claws. The hold-down is clamped onto a pipe by moving it to the open position, inserting the pipe through the opening and then closing the hold-down around the pipe. Again, the back includes a nail receiving aperture. A nail extending through the aperture is driven into a building member to secure the hold-down to the building member. An example of this type of hold-down is the Sioux Strap™ tube hanger, also manufactured by Sioux Chief Manufacturing Company, Inc.
U.S. Pat. No. 6,073,891 to Humber discloses a hybrid open type hold-down with a generally C-shaped body with a back and a pair of legs. A pipe receiver is formed between the legs and is accessible through the opening between the legs. Each leg has a inwardly projecting protrusion adjacent the opening which acts to retain the pipe in position. The body is made of a material which is sufficiently resilient that both legs of the C-shaped member deflect outwardly for receiving the pipe past the protrusions and into the pipe receiver. Nail receiving apertures are formed through both the back and one of the legs such that the hold-down may be secured to a building member in multiple orientations. The back and the leg with the nail receiving aperture are of generally identical construction.
If the hold-down of Humber '891 is installed with a nail through the aperture in the back, one of the legs will act to isolate the pipe from the building member. If the hold-down is installed with a nail through the aperture in the leg, and the back is toward the building member, the pipe will be isolated from the building member by the back. If the hold-down is installed with a nail through the aperture in the leg, and the opening is toward the building member, the pipe will be isolated from the building member by the protrusions and the air space therebetween.